This is a signature model by Roger Ingram, who has been active as a lead trumpet player for Woody Herman, Harry Connick Jr., and others. The inner rim diameter is about the same as a Bach 10-1/2 to 12. The rim is flat and slightly thick. The outer edge of the rim has a gentle cushion rim shape. The rim feels very comfortable on the mouth. The outer rim diameter feels like a Bach 12. The inner edge of the rim is gentle. The cup is a shallow bowl shape, similar to a Bach F. The throat is #28 (3.56mm). The backbore is about the same as a Warburton 4-5. It has a good response and a very brilliant and fast sound. When played gently, it has a warm sound with a wide range of expression. It's designed to make high notes quite easy. Recommended for those aiming for super high note hitting. Please feel free to ask any questions about the product.